It is proposed to study the role of cyclic AMP, calcium and protein phosphorylation in the peripheral nervous tissue. One approach is to determine the effect of neuronal activity on the state of phosphorylation Protein I in the superior cervical ganglia. A second approach is to determine the site of such phosphorylation in the Protein I molecule. A third approach is to determine the effect of impulse conduction on the state of phosphorylation of Protein I in the vas deferens. A fourth approach is to determine the site of such phosphorylation in the Protein I molecule. A fifth approach is to carry out cytochemical and radioimmunoassay studies, at the light and electromicroscope levels, on the distribution in the peripheral nervous system of Protein X, a protein found in mammalian brain.